Red Data Book category
Najas marina is a species of aquatic plant known by the common names spiny water nymph, spiny naiad and holly-leaved naiad. It is an extremely widespread species, reported across Europe, Asia, Africa, Australia, the Americas and many oceanic islands. It can be found in many types of freshwater and brackish aquatic habitat, including bodies of alkaline water.
Najas marina is an annual producing a slender, branching stem up to 40 or 45 centimeters in maximum length. The evenly spaced leaves are up to 4 centimeters long, 1 to 3 millimeters wide, and edged in tiny sawlike teeth. The leaf has prickles along its midvein. Minute flowers occur in the leaf axils. The plant is dioecious, with male and female flower types occurring on separate individuals.
Photos Achna dam 2/10/2016 by George Konstantinou